//#pragma GCC target("avx2") //#pragma GCC optimize("O3") //#pragma GCC optimize("unroll-loops") #include using namespace std; using ll=long long; using ull=unsigned long long; using pii=pair; using pll=pair; template using vvector=vector>; template using vvvector=vector>; template using vvvvector=vector>; #define Vector(type, name, ...) vector name(__VA_ARGS__) #define VVector(type, name, h, ...) \ vector> name(h, vector(__VA_ARGS__)) #define VVVector(type, name, h, w, ...) \ vector>> name( \ h, vector>(w, vector(__VA_ARGS__))) #define VVVVector(type, name, a, b, c, ...) \ vector>>> name( \ a, vector>>( \ b, vector>(c, vector(__VA_ARGS__)))) #define OVERLOAD_REP(_1, _2, _3, _4, name, ...) name #define REP1(n) for (int _ = 0; _ < (int)(n); _++) #define REP2(i,n) for (int i = 0; i < (int)(n); i++) #define REP3(i,l,r) for (int i = (int)(l); i < (int)(r); i++) #define REP4(i,l,r,d) for (int i = (int)(l); (d) > 0 ? i < (int)(r) : i > (int)(r); i += (d)) #define rep(...) OVERLOAD_REP(__VA_ARGS__,REP4,REP3,REP2,REP1)(__VA_ARGS__) #define OVERLOAD_RREP(_1, _2, _3, _4, name, ...) name #define all(x) (x).begin(),(x).end() #define rall(x) (x).rbegin(),(x).rend() template void chmin(T &a,T b){ if(a>b){ a=b; } } template void chmax(T &a,T b){ if(a0;NN/=10){ retu+=(char)(NN%10)+'0'; } reverse(retu.begin(),retu.end()); } os< ostream &operator<< (ostream &os, pair &p){ if(&os==&cerr){return os << "(" << p.first << ", " << p.second << ")";} return os << p.first << " " << p.second; } template basic_ostream &operator<<(basic_ostream &os, const Container &x) { bool first=true; if(&os==&cerr){os<<"[";} for(auto &y:x){ if(&os==&cerr){os<<(first?"":", ")< ostream &operator<<(ostream &os, const priority_queue &pq) { auto _pq = pq; vector retu; while(!empty(_pq)) retu.emplace_back(_pq.top()), _pq.pop(); return os << retu; } vector Subsets(const size_t bit){ vector subsets; size_t bit_=bit; while(bit_){ subsets.emplace_back(bit_); bit_-=1; bit_&=bit; } subsets.emplace_back(0); reverse(subsets.begin(),subsets.end()); return subsets; } long long pow_mod(long long x,long long n,long long mod){ if(n==0){ return 1LL; } if(n%2==0){ long long p=pow_mod(x,n/2,mod); return p*p%mod; } else{ long long p=pow_mod(x,n/2,mod); p*=p; p%=mod; p*=x; return p%mod; } } int main(){ int N; cin>>N; Vector(int,A,N); rep(i,N){ cin>>A[i]; } int ans=0; rep(i,N){ rep(j,N){ ans+=abs(i-j)*abs(A[i]-A[j]); } } cout<